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<pre><span class="sourceLineNo">001</span><a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Copyright (C) 2011 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<span class="sourceLineNo">004</span> *<a name="line.4"></a>
<span class="sourceLineNo">005</span> * $Id: VaadinApplicationListener.html 795 2013-12-11 18:48:15Z archie.cobbs $<a name="line.5"></a>
<span class="sourceLineNo">006</span> */<a name="line.6"></a>
<span class="sourceLineNo">007</span><a name="line.7"></a>
<span class="sourceLineNo">008</span>package org.dellroad.stuff.vaadin;<a name="line.8"></a>
<span class="sourceLineNo">009</span><a name="line.9"></a>
<span class="sourceLineNo">010</span>import org.springframework.context.ApplicationEvent;<a name="line.10"></a>
<span class="sourceLineNo">011</span>import org.springframework.context.event.ApplicationEventMulticaster;<a name="line.11"></a>
<span class="sourceLineNo">012</span>import org.springframework.context.event.SmartApplicationListener;<a name="line.12"></a>
<span class="sourceLineNo">013</span><a name="line.13"></a>
<span class="sourceLineNo">014</span>/**<a name="line.14"></a>
<span class="sourceLineNo">015</span> * A Spring {@link org.springframework.context.ApplicationListener} support superclass customized for use by<a name="line.15"></a>
<span class="sourceLineNo">016</span> * listeners that are part of a Vaadin application when listening to non-Vaadin application event sources.<a name="line.16"></a>
<span class="sourceLineNo">017</span> *<a name="line.17"></a>
<span class="sourceLineNo">018</span> * &lt;p&gt;<a name="line.18"></a>
<span class="sourceLineNo">019</span> * Listeners that are part of a Vaadin application should use this superclass if they are going to be registered<a name="line.19"></a>
<span class="sourceLineNo">020</span> * with non-Vaadin event multicasters. This will ensure that events are delivered {@linkplain ContextApplication#invoke<a name="line.20"></a>
<span class="sourceLineNo">021</span> * in the proper Vaadin application context} and memory leaks are avoided.<a name="line.21"></a>
<span class="sourceLineNo">022</span> * &lt;/p&gt;<a name="line.22"></a>
<span class="sourceLineNo">023</span> *<a name="line.23"></a>
<span class="sourceLineNo">024</span> * @param &lt;E&gt; The type of the event<a name="line.24"></a>
<span class="sourceLineNo">025</span> * @see VaadinExternalListener<a name="line.25"></a>
<span class="sourceLineNo">026</span> * @see ContextApplication#invoke<a name="line.26"></a>
<span class="sourceLineNo">027</span> * @see VaadinApplicationScope<a name="line.27"></a>
<span class="sourceLineNo">028</span> * @see SpringContextApplication<a name="line.28"></a>
<span class="sourceLineNo">029</span> */<a name="line.29"></a>
<span class="sourceLineNo">030</span>public abstract class VaadinApplicationListener&lt;E extends ApplicationEvent&gt;<a name="line.30"></a>
<span class="sourceLineNo">031</span>  extends VaadinExternalListener&lt;ApplicationEventMulticaster&gt; implements SmartApplicationListener {<a name="line.31"></a>
<span class="sourceLineNo">032</span><a name="line.32"></a>
<span class="sourceLineNo">033</span>    private final Class&lt;E&gt; eventType;<a name="line.33"></a>
<span class="sourceLineNo">034</span><a name="line.34"></a>
<span class="sourceLineNo">035</span>    /**<a name="line.35"></a>
<span class="sourceLineNo">036</span>     * Convenience constructor. Equivalent to:<a name="line.36"></a>
<span class="sourceLineNo">037</span>     * &lt;blockquote&gt;<a name="line.37"></a>
<span class="sourceLineNo">038</span>     *  {@link #VaadinApplicationListener(ApplicationEventMulticaster, Class, ContextApplication)<a name="line.38"></a>
<span class="sourceLineNo">039</span>     *      VaadinApplicationListener(multicaster, eventType, ContextApplication.get())}<a name="line.39"></a>
<span class="sourceLineNo">040</span>     * &lt;/blockquote&gt;<a name="line.40"></a>
<span class="sourceLineNo">041</span>     *<a name="line.41"></a>
<span class="sourceLineNo">042</span>     * @param multicaster the application event multicaster on which this listener will register<a name="line.42"></a>
<span class="sourceLineNo">043</span>     * @param eventType type of events this instance should receive (others will be ignored)<a name="line.43"></a>
<span class="sourceLineNo">044</span>     * @throws IllegalArgumentException if {@code eventType} is null<a name="line.44"></a>
<span class="sourceLineNo">045</span>     * @throws IllegalStateException if there is no {@link ContextApplication} associated with the current thread<a name="line.45"></a>
<span class="sourceLineNo">046</span>     */<a name="line.46"></a>
<span class="sourceLineNo">047</span>    public VaadinApplicationListener(ApplicationEventMulticaster multicaster, Class&lt;E&gt; eventType) {<a name="line.47"></a>
<span class="sourceLineNo">048</span>        this(multicaster, eventType, ContextApplication.get());<a name="line.48"></a>
<span class="sourceLineNo">049</span>    }<a name="line.49"></a>
<span class="sourceLineNo">050</span><a name="line.50"></a>
<span class="sourceLineNo">051</span>    /**<a name="line.51"></a>
<span class="sourceLineNo">052</span>     * Primary constructor. This results in this instance being registered as a listener on {@code multicaster}.<a name="line.52"></a>
<span class="sourceLineNo">053</span>     *<a name="line.53"></a>
<span class="sourceLineNo">054</span>     * @param multicaster the application event multicaster on which this listener will register<a name="line.54"></a>
<span class="sourceLineNo">055</span>     * @param eventType type of events this instance should receive (others will be ignored)<a name="line.55"></a>
<span class="sourceLineNo">056</span>     * @param application the associated Vaadin application<a name="line.56"></a>
<span class="sourceLineNo">057</span>     * @throws IllegalArgumentException if either parameter is null<a name="line.57"></a>
<span class="sourceLineNo">058</span>     */<a name="line.58"></a>
<span class="sourceLineNo">059</span>    public VaadinApplicationListener(ApplicationEventMulticaster multicaster, Class&lt;E&gt; eventType, ContextApplication application) {<a name="line.59"></a>
<span class="sourceLineNo">060</span>        super(multicaster, application);<a name="line.60"></a>
<span class="sourceLineNo">061</span>        if (eventType == null)<a name="line.61"></a>
<span class="sourceLineNo">062</span>            throw new IllegalArgumentException("null eventType");<a name="line.62"></a>
<span class="sourceLineNo">063</span>        this.eventType = eventType;<a name="line.63"></a>
<span class="sourceLineNo">064</span>    }<a name="line.64"></a>
<span class="sourceLineNo">065</span><a name="line.65"></a>
<span class="sourceLineNo">066</span>    /**<a name="line.66"></a>
<span class="sourceLineNo">067</span>     * Get the event type that this listener listens for.<a name="line.67"></a>
<span class="sourceLineNo">068</span>     */<a name="line.68"></a>
<span class="sourceLineNo">069</span>    public final Class&lt;E&gt; getEventType() {<a name="line.69"></a>
<span class="sourceLineNo">070</span>        return this.eventType;<a name="line.70"></a>
<span class="sourceLineNo">071</span>    }<a name="line.71"></a>
<span class="sourceLineNo">072</span><a name="line.72"></a>
<span class="sourceLineNo">073</span>    @Override<a name="line.73"></a>
<span class="sourceLineNo">074</span>    protected void register(ApplicationEventMulticaster eventSource) {<a name="line.74"></a>
<span class="sourceLineNo">075</span>        this.getEventSource().addApplicationListener(this);<a name="line.75"></a>
<span class="sourceLineNo">076</span>    }<a name="line.76"></a>
<span class="sourceLineNo">077</span><a name="line.77"></a>
<span class="sourceLineNo">078</span>    @Override<a name="line.78"></a>
<span class="sourceLineNo">079</span>    protected void unregister(ApplicationEventMulticaster eventSource) {<a name="line.79"></a>
<span class="sourceLineNo">080</span>        this.getEventSource().removeApplicationListener(this);<a name="line.80"></a>
<span class="sourceLineNo">081</span>    }<a name="line.81"></a>
<span class="sourceLineNo">082</span><a name="line.82"></a>
<span class="sourceLineNo">083</span>    @Override<a name="line.83"></a>
<span class="sourceLineNo">084</span>    public final void onApplicationEvent(ApplicationEvent event) {<a name="line.84"></a>
<span class="sourceLineNo">085</span>        E castEvent;<a name="line.85"></a>
<span class="sourceLineNo">086</span>        try {<a name="line.86"></a>
<span class="sourceLineNo">087</span>            castEvent = this.eventType.cast(event);<a name="line.87"></a>
<span class="sourceLineNo">088</span>        } catch (ClassCastException e) {<a name="line.88"></a>
<span class="sourceLineNo">089</span>            // should not happen<a name="line.89"></a>
<span class="sourceLineNo">090</span>            return;<a name="line.90"></a>
<span class="sourceLineNo">091</span>        }<a name="line.91"></a>
<span class="sourceLineNo">092</span>        final E castEvent2 = castEvent;<a name="line.92"></a>
<span class="sourceLineNo">093</span>        this.handleEvent(new Runnable() {<a name="line.93"></a>
<span class="sourceLineNo">094</span>            @Override<a name="line.94"></a>
<span class="sourceLineNo">095</span>            public void run() {<a name="line.95"></a>
<span class="sourceLineNo">096</span>                VaadinApplicationListener.this.onApplicationEventInternal(castEvent2);<a name="line.96"></a>
<span class="sourceLineNo">097</span>            }<a name="line.97"></a>
<span class="sourceLineNo">098</span>        });<a name="line.98"></a>
<span class="sourceLineNo">099</span>    }<a name="line.99"></a>
<span class="sourceLineNo">100</span><a name="line.100"></a>
<span class="sourceLineNo">101</span>    /**<a name="line.101"></a>
<span class="sourceLineNo">102</span>     * Handle a listener event. When this method is invoked, it will already be within the context<a name="line.102"></a>
<span class="sourceLineNo">103</span>     * of the {@link ContextApplication} with which this listener is associated.<a name="line.103"></a>
<span class="sourceLineNo">104</span>     * The current {@link ContextApplication} is also available via {@link ContextApplication#get}.<a name="line.104"></a>
<span class="sourceLineNo">105</span>     *<a name="line.105"></a>
<span class="sourceLineNo">106</span>     * @see ContextApplication#get<a name="line.106"></a>
<span class="sourceLineNo">107</span>     */<a name="line.107"></a>
<span class="sourceLineNo">108</span>    protected abstract void onApplicationEventInternal(E event);<a name="line.108"></a>
<span class="sourceLineNo">109</span><a name="line.109"></a>
<span class="sourceLineNo">110</span>    /**<a name="line.110"></a>
<span class="sourceLineNo">111</span>     * Determine whether this listener actually supports the given event type.<a name="line.111"></a>
<span class="sourceLineNo">112</span>     *<a name="line.112"></a>
<span class="sourceLineNo">113</span>     * &lt;p&gt;<a name="line.113"></a>
<span class="sourceLineNo">114</span>     * The implementation in {@link VaadinApplicationListener} tests whether {@code eventType}<a name="line.114"></a>
<span class="sourceLineNo">115</span>     * is assignable to the type given in the constructor. Subclasses may override as desired.<a name="line.115"></a>
<span class="sourceLineNo">116</span>     */<a name="line.116"></a>
<span class="sourceLineNo">117</span>    @Override<a name="line.117"></a>
<span class="sourceLineNo">118</span>    public boolean supportsEventType(Class&lt;? extends ApplicationEvent&gt; eventType) {<a name="line.118"></a>
<span class="sourceLineNo">119</span>        return this.eventType.isAssignableFrom(eventType);<a name="line.119"></a>
<span class="sourceLineNo">120</span>    }<a name="line.120"></a>
<span class="sourceLineNo">121</span><a name="line.121"></a>
<span class="sourceLineNo">122</span>    /**<a name="line.122"></a>
<span class="sourceLineNo">123</span>     * Determine whether this listener actually supports the given source type.<a name="line.123"></a>
<span class="sourceLineNo">124</span>     *<a name="line.124"></a>
<span class="sourceLineNo">125</span>     * &lt;p&gt;<a name="line.125"></a>
<span class="sourceLineNo">126</span>     * The implementation in {@link VaadinApplicationListener} always returns true. Subclasses may override as desired.<a name="line.126"></a>
<span class="sourceLineNo">127</span>     */<a name="line.127"></a>
<span class="sourceLineNo">128</span>    @Override<a name="line.128"></a>
<span class="sourceLineNo">129</span>    public boolean supportsSourceType(Class&lt;?&gt; sourceType) {<a name="line.129"></a>
<span class="sourceLineNo">130</span>        return true;<a name="line.130"></a>
<span class="sourceLineNo">131</span>    }<a name="line.131"></a>
<span class="sourceLineNo">132</span><a name="line.132"></a>
<span class="sourceLineNo">133</span>    /**<a name="line.133"></a>
<span class="sourceLineNo">134</span>     * Get ordering value.<a name="line.134"></a>
<span class="sourceLineNo">135</span>     *<a name="line.135"></a>
<span class="sourceLineNo">136</span>     * &lt;p&gt;<a name="line.136"></a>
<span class="sourceLineNo">137</span>     * The implementation in {@link VaadinApplicationListener} always returns zero. Subclasses may override as desired.<a name="line.137"></a>
<span class="sourceLineNo">138</span>     */<a name="line.138"></a>
<span class="sourceLineNo">139</span>    @Override<a name="line.139"></a>
<span class="sourceLineNo">140</span>    public int getOrder() {<a name="line.140"></a>
<span class="sourceLineNo">141</span>        return 0;<a name="line.141"></a>
<span class="sourceLineNo">142</span>    }<a name="line.142"></a>
<span class="sourceLineNo">143</span>}<a name="line.143"></a>
<span class="sourceLineNo">144</span><a name="line.144"></a>




























































</pre>
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